Ultrasonic diagnostic apparatus for controlling the surface temperature of a probe

Abstract

A technology is disclosed for holding the test subject contact surface temperature below a predetermined value without providing a temperature sensor or setting ultrasonic wave output excessively low and, according to this technology, reflex time t 1, which passes through oil 6, is reflected by the inner surface of window 5, and is returned via oil, and reflex time t 2, which passes through the window, is reflected by the outer surface of the window, and returned via window or oil, are detected, sound velocity of window=(thickness of window×2)/( t 2 −t 1) is measured, and the surface temperature of the window is detected from this measured sound velocity.

1. An ultrasonic diagnostic apparatus, comprising:
 an ultrasonic probe including a window configure for contact with a test subject, the window having an inner surface and an outer surface; 
 a sound velocity calculation means for calculating the sound velocity of ultrasonic waves based on the difference between the reflex time of ultrasonic wave reflected from the inner surface of the window and the reflex time of ultrasonic wave reflected from the outer surface of the window and the thickness of the window; 
 a temperature calculation means for calculating the temperature of the window based on sound velocity calculated by the sound velocity calculation means; and 
 an ultrasonic wave output control means for controlling ultrasonic wave output based on temperature calculated by the temperature calculation means. 
 
     
     
       2. The ultrasonic diagnostic apparatus according to  claim 1 , further comprising:
 a memory means for storing the thickness of said window and the thickness of said fluid obtained by detecting said reflex times of ultrasonic waves under a certain temperature beforehand and performing calibrations respectively, for the window and the fluid; and, wherein 
 said sound velocity calculation means calculates the sound velocity of ultrasonic waves based on the thickness of the window or the thickness of the fluid stored by the memory means. 
 
     
     
       3. An ultrasonic diagnostic apparatus, comprising:
 an ultrasonic probe including a window configure for contact with a test subject, the window having an inner surface; 
 a sound velocity calculation means for calculating the sound velocity of ultrasonic waves based on the reflex time of ultrasonic wave passing through fluid wherein sonic elements vibrate and reflected from the inner surface of the window, and the thickness of the fluid; 
 a temperature calculation means for calculating the temperature of the fluid based on the sound velocity calculated by the sound velocity calculation means; and 
 an ultrasonic wave output control means for controlling ultrasonic wave output based on temperature calculated by the temperature calculation means. 
 
     
     
       4. The ultrasonic diagnostic apparatus according to  claim 3 , further comprising:
 a memory means for storing the thickness of said window and the thickness of said fluid obtained by detecting said reflex times of ultrasonic waves under a certain temperature beforehand and performing calibrations respectively, for the window and the fluid; and, wherein 
 said sound velocity calculation means calculates the sound velocity of ultrasonic waves based on the thickness of the window or the thickness of the fluid stored by the memory means.